Cybus h



. O. H. HAW KINS.

S1ide-Va1ve.'

Patented May 4,1880.

/ I v A N.PETERS, PHOTO LITMOGRAFHER WASHINGTON o C UNITED STATES PATENTOFFICE.

CYRUS H. HAWKINS, OF NEW YORK, N. Y.

SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 227,165, dated May 4,1880.

Application filed October 15, 1879.

To all whom it may concern Be it known that I, Ovens H. HAWKINs, of

.New York city, in the county and State of New York, have inventedcertain new and useful Improvements relating to Slide-Valves for Steamand Air Engines, of which the following is a specification.

I make my valves perfectly balanced. I provide a cut-off valve workingon and over the principal slide, whiclris also perfectly balanced, andwhich is capable of ready adjustment within wide limits. The cut-off maybe adjusted automatically; but I will show it adapted for adjustment byhand.

The following is a description of what 1 consider the best means ofcarrying out the invention.

The accompanying drawings form a part of the specification.

Figure 1 is a longitudinal section, and Fig. 2 is a plan view with allabove the main slide removed. The figures show the parts which show thenovelty with so much of the other parts as is necessary to show theirrelation thereto. Fig. 3 is a plan view with only the top plate removed.

Similar letters of reference indicate corresponding parts in all thefigures.

Referring to the drawings, A is a portion of the cylin der-castin g,form ed with ports a, which may be of any ordinary or suitable lengthand contour to lead the steam to and from the ends of the cylinder. A isthe steam-chest; A the top plate or steam-chest cover, formed with twoports, (0 ,219, the cut-off chest, and A the top plate therefor. Asufficient opening, a, receives the steam through a pipe (notrepresented) leading from the boiler.

The main slide is indicated by B, some of its parts being designated byadditional marks, as B B The stem or rod b extends out through astuffing-box and receives the proper reciproeating motion from anyordinary or suitable connections. (Not shown.)

The slide is carefully finished to present a strictly uniform thicknessat all points exactly equal to the space between the cylinder-face A andthe steam-chest cover A The under face of the cover A is recessed, asindicated at m,

each to a length and breadth exactly corresponding with the port a,which is opposite.

B B are cross-pieces, accurately arranged and finished to give theproper lead and lap. Each is formed with openings 1), as shown. 13 is acentral cross-bar.

Ois an opening for the exhaust-steam. There is sufficient space alongeach side of the main slide to allow the exhaust to escape freely fromeither end through this opening. The under side of A is formed withrecesses m, corresponding in form and position to the ports a D D aretwo independent cut-off valves, accurately finished as to height toexactly fill the space between the plates A and A They are tapped toreceive right and left hand screwthreads formed on the cut-off rod E.The cutoff valves D are each formed with openings (1, as shown.

The cut-off rod E is provided with a squared part, E, outside of thestuffing-box, which allows of ready operating with a forked wrench orother convenient device to turn ,it, as required, to set the cutoffvalves D D nearer together or farther apart, and thus to change thepoint of cut-ofi.

The rod E is connected to the eccentric-rod I, not only by the ordinaryknuckle H, but also by'a swivel-joint, Gr, which allows the rod E to beturned to any extent desired. The turning of this rod by means of thesquared part E changes the cut-oii by moving the valves D D nearertogether or farther apart without moving the rod E endwise at all. Whenit is desired to hold it firmly against any further change this may beeffected by tightening a jam-nut.

Modifications may be made in many of the details. The apertures b may bemade sufficiently large to allow them to aid in inducting and eductingthe steam, or they may be contracted much smaller than here shown, solong as they are sufficient to allow a free flow of the steam to andfrom the-cavities m. The pressure in these cavities must be alwaysexactly equal to that in the ports.

The openings d in the cutoff valves D perform the simple but importantfunction of in suring that the pressure in each cavity m is alwaysexactly equal to that in the port below.

It follows that the valves are all worked in absolute balance.

The swivel-joint by which the cut-off rod E connects with its operatingmechanism may be varied in construction within wide limits, so as itallows the rod to be turned as required, without inducing anylongitudinal motion of the rod, but only to change the distances apartof the cut-off valves D D. I can connect a device operated by agovernor, if desired.

I claim as my invention- The covers A A formed with recesses m m,corresponding to the ports below, in combination with the main slide Band cut-off valves D, having apertures b d, as shown, and 15 with theright and left screw-threaded cut-ofl rod E, adapted to serve with asuitable swivcling connection to the eccentric-rod, as herein set forth.

In testimony whereof I have hereunto set 20 my hand this 9th day ofOctober, 1879, in the presence of two subscribing witnesses.

CYRUS H. HAWKINS.

Witnesses:

M. L. WILOOX, CHAS. F. WILOOX.

